Optical switch

ABSTRACT

In an optical switch for routing an optical signal, a deflecting member is mounted movably on a base and is tiltable about a fulcrum shaft so as to deflect the optical signal. Multiple elongate cantilevers are disposed on the base and are arranged around the deflecting member. Each cantilever has a coupling end portion connected to the base and opposite to a hammer end portion disposed on a periphery of the deflecting member. Control units are disposed on the base, and are operably and respectively associated with the cantilevers so as to control movement of the cantilevers to an appropriate one of a suspending position, where the hammer end portion is spaced apart from the deflecting member, and a pumping position, where the hammer end portion strikes the deflecting member, thereby forcing the deflecting member to tilt to a desired direction about the fulcrum shaft.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of U.S. Provisional Patent ApplicationNo. 60/405,748, filed on Aug. 22, 2002.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an optical switch, more particularly to an.optical switch for routing an optical signal at high speeds.

2. Description of the Related Art

Due to the requirement of high-speed data transmission in Internetapplications, optical switches are often used in image display, datarecording, data transmission and data processing. However, aconventional mechanical optical switch is expensive and has acomplicated construction and low reliability. Moreover, the switchingspeed (e.g., 1 millisecond to 100 milliseconds) of a conventionalmechanical optical switch cannot meet the demands of high-speed networkcommunication application.

Generally, conventional mechanical switch includes a deflecting devicehaving a movable deflector. First, two assumptions are made to simplifyanalysis.

-   -   1. The moment of linear displacement of the deflector is greater        than, about 3.14 timer, the angular moment of the deflector when        tilting.    -   2. The inertial mass of the deflecting device is about 3.1.4        times that of the deflector.

If the deflector is made of silicon with a density of 2.33 g/cm³, andhas a volume of 90×90×4 μm³, the force f and the power P required tomove the deflector by a distance of 1.2 μm within a period of 40nanoseconds are as follows: $\begin{matrix}{f = {2 \times m \times \frac{s}{t^{2}}}} \\{= {2 \times 7.55 \times 10^{- 8} \times \frac{1.2 \times 10^{- 4}}{\left( {4 \times 10^{- 8}} \right)^{2}}}} \\{= {1.13 \times 10^{4}\quad{dynes}\quad\left( {{1/9}\quad{Newton}} \right)}} \\{P = {f \times {- \frac{s}{t}}}} \\{= {1.13 \times 10^{4} \times \frac{1.2 \times 10^{- 4}}{4 \times 10^{- 8}}}} \\{= {34 \times 10^{6}\quad{watts}\quad\left( {34\quad{Megawatts}} \right)}}\end{matrix}$

Both the required force f and power P are not available in conventionalintegrated circuits. Particularly, since it is difficult to apply aforce of 1 Newton to a tiny space smaller than a tip of a hair strand,the switching speed of the conventional mechanical optical switch isthus limited to millisecond-levels.

To solve the above problem, various techniques for mechanical opticalswitches, such as liquid crystal, piezoelectric, sound wave, temperatureand electrostatic, lave been proposed heretofore in response to growingrequirements. However, the switching speeds of mechanical opticalswitches using the above techniques can only be promoted to microsecondlevels.

SUMMARY OF THE INVENTION

Therefore, the object of the present invention is to provide an opticalswitch for routing an optical signal at high speeds.

According to the present invention, there is provided an optical switchfor routing an optical signal. The optical switch comprises:

-   -   a base having a fulcrum shaft;    -   a deflecting member mounted movably on the base and tiltable        about the fulcrum shaft so as to be adapted for deflecting the        optical signal;    -   a plurality of elongate cantilevers disposed on the base and        arranged around the deflecting member, each of the cantilevers        having a hammer end portion disposed on a periphery of the        deflecting member, and a coupling end portion opposite to the        hammer end portion and connected to the base, each of the        cantilevers being operable so as to move from a suspending        position, where the cantilever is bent such that the hammer end        portion is spaced apart from the deflecting member, thereby        storing a restoring force in the cantilever, to a pumping        position, where the hammer end portion strikes the deflecting        member so as to force the deflecting member to tilt about the        fulcrum shaft; and    -   a plurality of control units, each of which is disposed on the        base, is operably associated with a corresponding one of the        cantilevers, and is capable of controlling the corresponding one        of the cantilevers to move to an appropriate one of the        suspending position and the pumping position so as to enable the        deflecting member to tilt to a desired direction.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will becomeapparent in the following detailed description of the preferredembodiments with reference to the accompanying drawings, of which:

FIG. 1 is a schematic sectional view showing the first preferredembodiment of an optical switch according to the present invention;

FIG. 2 is a schematic sectional view showing elongate cantilevers of thefirst preferred embodiment in an initial state;

FIG. 3 is a schematic top view showing a deflecting member of the firstpreferred embodiment, viewed along line III-III of FIG. 2;

FIG. 4 is a fragmentary schematic sectional view showing one cantileverof the first preferred embodiment at a suspending position;

FIG. 5 is a fragmentary schematic sectional view showing cane cantileverof the first preferred embodiment when moved from the suspendingposition to a pumping position;

FIG. 6 is a schematic top view showing electromagnets of control unitsof the first preferred embodiment, viewed along line VI-VI of FIG. 2;

FIG. 7 is a timing diagram illustrating how the first preferredembodiment controls two cantilevers;

FIG. 8 is a schematic sectional view showing the second preferredembodiment of an optical switch according to the present invention;

FIG. 9 is a schematic top view showing a deflecting member of a thirdpreferred embodiment of an optical switch according to the presentinvention;

FIG. 10 is a schematic sectional view showing the deflecting member ofthe third preferred embodiment, taken along line X-X of FIG. 9;

FIG. 11 is a fragmentary schematic sectional view showing an elongatecantilever of the third preferred embodiment in an initial state;

FIG. 12 is a fragmentary schematic sectional view showing one cantileverof the third preferred embodiment at a suspending position;

FIG. 13 is a fragmentary schematic sectional view showing one cantileverof the third preferred embodiment when moved from the suspendingposition to a pumping position;

FIG. 14 is a fragmentary schematic top view showing the fourth preferredembodiment of an optical switch according to the present invention whena sliding actuator is disposed at a holding position;

FIG. 15 is a fragmentary schematic sectional view showing one cantileverof the fourth preferred embodiment at a suspending position, taken alongline XV-XV of FIG. 14;

FIG. 16 is a fragmentary schematic view showing the sliding actuator ofthe fourth preferred embodiment at a releasing position; and

FIG. 17 is a fragmentary schematic sectional view showing one cantileverof the fourth preferred embodiment at a pumping position, taken alongline X V II-X V II of FIG. 16.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Before the present invention is described in greater detail, it shouldbe noted that like elements are denoted by the same reference numeralsthroughout the disclosure.

Referring to FIG. 1, the first preferred embodiment of an optical switch1 according to the present invention is shown. In this embodiment, theoptical switch 1 is adapted to be installed in an optical router (notshown) and to be connected electrically to a drive chip (not shown) anda digital network processor chip (not shown). The optical switch 1includes an input module 3, a plurality of output modules 4, a base 2, adeflecting member 5, a plurality of elongate cantilevers 51, and aplurality of control units 7.

The input module 3 is adapted for providing the optical signal to thedeflecting member 5. In this embodiment, the input module 3 includes aninput port 31 provided with an input optical fiber 32 therein. Althoughthe input optical fiber 32 is used for transmission of the opticalsignal in this embodiment, an optical waveguide serving as a medium fortransmitting optical signals can replace the input optical fiber 32. Inthis embodiment, the input optical fiber 32 has an exit end 321 having across-section with a diameter of 60 μm. A distance between the exit end321 and the deflecting member 5 is less than 0.2 mm. In this embodiment,the input module 3 is disposed on one side of the deflecting member 5.

The base 2 is provided with a fulcrum shaft 22. In this embodiment, thebase 2 is formed with a deflector receiving groove 20 that has a concavebottom wall 201 provided with the fulcrum shaft 22 thereon. The fulcrumshaft 22 has a height within a range from 8 μm to 9.9 μm, and a diameterof 10 μm.

Referring to FIGS. 2 and 3, the deflecting member 5 is mounted movablyon the base 2 and is tiltable about the fulcrum shaft 22 so as to beadapted for deflecting the optical signal from the input module 3. Inthis embodiment, the deflecting member 5 includes a deflector 51disposed on the fulcrum shaft 22, and a set of suspension arms 52arranged around the deflector 51 and interconnecting the deflector 51and the base 2, as shown in FIG. 3.

In order to reduce the dispersion in transmission of the optical signalvia the input module 3, the input optical fiber 32 is chosen to be aself-focusing fiber with a low index grading rate. A self-focusing fiberis obtained with a “sech ( )” profiled refractive index distribution.The refractive index n(r) of the input optical fiber 32 can be expressedas${n(r)} = {{{n(0)} \times \sec\quad{h\left( {a \times r} \right)}} = \frac{2 \times {n(0)}}{{\mathbb{e}}^{({a \times r})} + {\mathbb{e}}^{({a \times r})}}}$where “r” is a radial distance between a test point and an axis of theinput optical fiber 32, and “a” is an index grading constant. In thiscondition, the optical signal will be focused at a length of${F = {\frac{n}{\left( {2 \times a} \right)} = {{7.854\quad{mm}\quad{when}\quad a} = {2\quad{per}\quad{cm}}}}},$regardless of the wavelength or incident angle of the optical signal aslong as the optical signal is focused within a deflecting area of thedeflecting member 5. Consequently, when the length of the input opticalfiber 32 is equal to an integral multiple of a half period, angulardivergence at the exit end 321 is${2{n(0)} \times {\tan^{- 1}\left( \frac{d}{f} \right)}} = {{0.0238\quad{{Rad}.}} = {1.36\quad{{degree}.}}}$

In other words, if the distance between the deflector 51 and the exitend 321 is 6 mm, the diameter of the deflector 51 should be at least 86μm. if the distance between the deflector 51 and each output module 4 is8 mm, the diameter of an output optical fiber 42 of each output module 4should be at least 200 μm.

In this embodiment, the deflector 51 has a low inertia mass, and isformed as a disk with a thickness of 4 μm and a diameter of 90 μm, whichmeets the above condition due to the distance between the deflector 51and the exit end 321 being less than 6 mm. The deflector 51 has a topsurface 512 coated with a highly reflective gold film, and a bottomsurface 515 formed with an O-ring shaped bump 516 at the center to fiton a tip of the fulcrum shaft 22 and a plurality of magnetic pads 514(four in this embodiment) with an area of 300 μm² corresponding to aplurality of permanent magnets 21, each of which is mounted on thebottom wall 201 of the deflector receiving groove 20 in the base 2 andhas a magnetic flux of 0.25 tesla, a thickness of 2 μm and an area of600 μm². The deflector 51 further has a plurality of extensions 513extending radially from a periphery of the deflector 51, as shown inFIG. 3. In this embodiment, each suspension arm 52 has a serpentineconfiguration with a cumulative length not less than 600 μm, and a widththat increases in a direction from the deflector 51 to the base 2. Amaximum displacement of each suspension arm 52 at an end point is 0. 84μm such that the strain of each suspension arm 52 is less than 0.14%.Each suspension arm 52 has a cross-section with a size of 2×2, μm²fabricated through a micro-electromechanical process. In order to reduceunwanted oscillations of the suspension arms 52, each suspension arm 52can be surrounded with a cushioning member (not shown) for dampingpurposes.

In this embodiment, four output modules 4 (only two are shown in FIG. 1)are disposed on another side of the deflecting member 5 opposite to saidone side. Tilting of the deflecting member 5 to a desired directionresults in receipt of the optical signal deflected by the deflectingmember 5 by a selected one of the output modules 4. Each output module 4includes an output port 41 provided with the output optical fiber 42therein. The output optical fiber 42 can be similarly replaced using anoptical waveguide. The output optical fiber 42 of each output module 4has an entrance end 421 having a cross-section. with a diameter of 200μm, and has a cross-section with a diameter that is gradually reducedfrom 200 μm to 60 μm. A distance between the deflecting member 5 and theentrance end 421 of each output module 4 is equal to 6. 8 mm (less than8 mm) that meets the above condition.

Preferably, the input module 3 has an axis 311 that forms an angleranging from 0° to 180° with an imaginary axis 411 parallel to theoutput optical fibers 42 of the output modules 4. In this embodiment,the angle is 90°. The axes 311, 411 intersect at a center of the topsurface 512 of the deflector 51. The output optical fibers 42 are evenlydistributed around and respectively form a 3.55° angle with the axis411. The 3.55° angle is coordinated with two times of the achievabletilting angle of the deflector 51.

With further reference to FIGS. 2, 4 and 5, the cantilevers 61 aredisposed on the base 2 and are arranged around the deflecting member 5.Each cantilever 61 has a hammer end portion 63 disposed on a peripheryof the deflecting member 5, and a coupling end portion 62 opposite tothe hammer end portion 63 and connected to the base 2. Each cantilever61 is operable so as to move from a suspending position, where thecantilever 61 is bent such that the hammer end portion 63 is spacedapart from the deflecting member 5, as shown in FIG. 4, thereby storinga restoring force in the cantilever 61, to a pumping position, where thehammer end portion 63 strikes a corresponding one of the extensions 513of the deflector 51 so as to force the deflector 51 to tilt about thefulcrum shaft 22, as shown in FIG. 5. In this embodiment, eachcantilever 61 has a length of 1.5 mm and a cross-section with a size of3200 μm².

With further reference to FIGS. 4 to 6, each control unit 7 is disposedon the base 2, is operably associated with a corresponding one of thecantilevers 61, and is capable of controlling the corresponding one ofthe cantilevers 61 to move to an appropriate one of the suspendingposition and the pumping position so as to enable the deflector 51 ofthe deflecting member 5 to tilt to a desired direction. In thisembodiment, each control unit 7 includes a mounting member 71, anelectromagnet 72, an electrostatic plate 740, and an L-shaped actuator73. The mounting member 71, which is made of a non-magnetic material(such as silicon), is disposed on the base 2 adjacent to thecorresponding one of the cantilevers 61, and has a lower mounting plate711 formed with two mounting holes 710, and an upper mounting plate 712.The thickness of the lower mounting plate 711 is preferably 200 μm. Eachof the lower and upper mounting plates 711, 712 has a shape thatconverges in a 45° angle and in a direction toward the deflector 57. soas not to block light transmission from the input module 3 to theselected output module 4. The electromagnet 72 is mounted on themounting member 71, and has two magnet cores 721 mounted in the mountingholes 710 in the lower mounting plate 771, and a coil 722 surroundingthe lower mounting plate 711, as shown in FIG. 6. The actuator 73 leasan intermediate pivot portion 731 connected pivotally to the mountingmember 71 and pivotable about a pivot axis (A) transverse to the fulcrumshaft 22, an elongate hooking portion 732 connected to the intermediatepivot portion 731 and extending through a through hole 713 in the magnetcore 721 and a through hole 613 in the corresponding one of thecantilevers 61, and an electrostatically-attractive interacting portion733 connected to the intermediate pivot portion 731 and transverse tothe hooking portion 732. The electrostatic plate 740 is mounted on theupper mounting plate 712 and is disposed above the interacting portion733 of the actuator 7. In this embodiment, the cantilevers 61 are madeof magnetically-attractive. The electromagnet 72 is operable in one ofan energized state and a de-energized state. The electromagnet 72attracts the hammer end portion 63 when in the energized state so as toenable the actuator 73 to pivot about the pivot axis (A) such that thehooking portion 732 moves and holds the lifted hammer end portion 63 ofthe corresponding one of the cantilevers 61 to dispose the correspondingone of the cantilevers 61 in the suspending position, as shown in FIG.4. The electromagnet 72 pre-releases the hammer end portion 63 of thecorresponding cantilever 61 when in the de-energized state while theelectrostatic plate 740 is operable to attract the interacting portion733 so as to enable the actuator 73 to pivot about the pivot axis (A)such that the hooking portion 732 permits movement of the hammer endportion 63 of the corresponding one of the cantilevers 61 to dispose thecorresponding one of the cantilevers 61 in the pumping position byvirtue of the restoring force in the corresponding one of thecantilevers 61. It is noted that, if each cantilever 61 is magneticallyattractive and has an area large enough to be attracted by theelectromagnet 72 so as to dispose the cantilever 61 in the suspendingposition, the actuator 73 can be omitted.

The optical switch 1 of the present invention can be applied to acommunication system with 300 channels, such as in the DWDM (DenseWavelength Divided multiplexing) mode operations, for transmission of128-bit data packets at a speed of 40 Gbps (Giga bits per second).Referring to FIG. 7, the cantilevers 61 are disposed in the suspendingposition at initial time t_(o) when the cantilevers 61 are in theenergized state. A first data packet can be transmitted within a periodfrom t_(o) to t₁ (about 0.96 μs). The control unit 7 controls theelectrostatic plate 740 corresponding to one cantilever 61 to releasethe interacting portion 733 of the actuator 73 associated with said onecantilever 61 at t₁. As such, a second data packet can be transmitted toa desired one of the output modules 42 within a period from t₂ to t₃(about 0.96 μs), and the time period from t₁ to t₂ is about 10 ns.Thereafter, the control unit 7 controls the electrostatic plate 740corresponding to another cantilever 61 to release the interactingportion 733 of the actuator 73 associated with said another cantilever61 at t₃. As such, a third data packet can be transmitted to a desiredone of the output modules 42 within a period from t₄ to is (about 0.96μs), the time period from t₃ to t₄ being about 10 ons. It is noted thata third data packet should be transmitted to a desired one of the outputmodules 42 at t₄. It takes about 1 μs to move the cantilever 61 from thepumping position to the suspending position. The period from t₂ to T_(s)is 1.93 μs. Therefore, the optical switch 1 of this invention can beswitched in sufficient time during data transmission.

FIG. 8 illustrates the second preferred embodiment of an optical switchaccording to this invention, which is a modification of the firstpreferred embodiment. Unlike the embodiment of FIG. 1, the input module3′ is substantially aligned with the fulcrum shaft 22. The outputmodules 4′ are disposed around the input module 3′.

FIG. 9 to 11 illustrate the third preferred embodiment of an opticalswitch according to this invention, which is a modification of the firstpreferred embodiment. Unlike the previous embodiment, the deflectingmember 5′ includes a deflector 51′ having a deflecting side 512′ and amounting side 515′ opposite to the deflecting side 512′. The deflector51′ is formed with a plurality of projections 522 extending radiallyfrom a periphery of the deflector 51′, as shown in FIG. 9. The base 2′is formed with a deflector receiving recess 24. The fulcrum shaft 22 isdisposed in the deflector receiving recess 24. The deflector receivingrecess 24 is confined by a confining wall 25 that extends parallel tothe fulcrum shaft 22. The confining wall 25 is formed with a pluralityof guiding grooves 251 corresponding to the projections 522 on thedeflector 51′ such that the projections 522 are positioned movably andrespectively well within the guiding grooves 251 when the mounting side515′ of the deflector 51′ is disposed on the fulcrum shaft 22 in thedeflector receiving recess 24, as shown in FIG. 10. The deflectingmember 5′ further includes a set of magnetic plates 514′ mounted on themounting side 515′ of the deflector 51′. The base 21 is further providedwith a set of permanent magnet blocks 21′ in the recess 24 andcorresponding to the magnetic plates 514′ for stabilizing the deflector51′ when one of the cantilevers 61 strikes the deflector 51′.

Referring to FIG. 11, each control unit 7′ includes a driving member71′, a first electromagnet member 75, a second electromagnet member 76,and an L-shaped actuator 73′.

The driving member 71′ is connected pivotally to the base 21 and isdisposed on the base 2′ adjacent to the corresponding one of thecantilevers 61. The driving member 71′ has a first intermediate pivotportion 714 connected pivotally to the base 2′ and pivotable about afirst pivot axis (B) transverse to the fulcrum shaft 22, a driving endportion 715 connected to the first intermediate pivot portion 714 anddisposed above the corresponding one of the cantilevers 61 and adjacentto the deflecting member 5′, and a magnetically-attractive end portion716 opposite to the driving end portion 715 and connected to the firstintermediate pivot portion 714. In this embodiment, themagnetically-attractive end portion 716 is formed with a magnetic plate717.

The first electromagnet member 75 is mounted on the base 2′ and isdisposed adjacent to and below the magnetic plate 717 on the end portion716 of the driving member 71′.

The second electromagnet member 76 is mounted on the driving end portion715 of the driving member 71′.

The L-shaped actuator 73′ has a second intermediate pivot portion 731′connected pivotally to the driving end portion 715 of the driving member71′ and pivotable about a second pivot axis (C) transverse to thefulcrum shaft 22 and parallel to the first pivot axis (B), an elongatehooking portion 732′ connected to the second intermediate pivot portion731′, and extending through a through hole 7151 in the driving endportion 715 and a through hole 613 in the corresponding one of thecantilevers 61, and a magnetically-attractive interacting portion 733′connected to the second intermediate pivot portion 731′ and disposedadjacent to the second electromagnet member 76.

The first electromagnet member 75 is energized to attract themagnetically-attractive end portion 716 of the driving member 71, so asto enable the driving member 71′ to pivot about the first pivot axis (B)such that the hooking portion 732′ of the actuator 73′ moves with thedriving end portion 715 of the driving member 71′ so as to hook thehammer end portion 63 of the corresponding one of the cantilevers 61when the second electromagnet member 76 is energized to attract theinteracting portion 733′ of the actuator 73′ in order to dispose thecorresponding one of the cantilevers 61 in the suspending position, asshown in FIG. 12.

The second electromagnet member 76 is energized (see FIG. 12), and isde-energized to release the interacting portion 733′ of the actuator 73′and enable pivoting movement of the actuator 73′ such that the hookingportion 732′ of the actuator 73′ permits movement of the hammer endportion 63 of the corresponding one of the cantilevers 61 to dispose thecorresponding one of the cantilevers 61 in the pumping position byvirtue of the restoring force of the corresponding one of thecantilevers 61, as shown in FIG. 13.

FIG. 14 to 17 illustrate the fourth preferred embodiment of an opticalswitch according to this invention, which is a modification of the firstpreferred embodiment. Unlike the previous embodiments, each control unit8 includes a mounting member 81, a first electromagnet member 82, amagnetically-attractive working plate 83, a second electromagnet member84, and a sliding actuator 85.

The mounting member 81 is disposed on the base 2′ adjacent to thecorresponding one of the cantilevers 61′.

The first electromagnet member 82 is mounted on the mounting member 81.

The working plate 83 is disposed below the first electromagnet member82, and has a connecting end 831 connected to the mounting member 81,and a driving end 832 opposite to the connecting end 831, and disposedbelow the hammer end portion 63′ of the corresponding one of thecantilevers 61′.

The second electromagnet member 84 is mounted on the mounting member 81,and is disposed adjacent to the coupling end portion 62′ of thecorresponding one of the cantilevers 61′.

The actuator 85 is disposed slidably between the base 2′ and thecorresponding one of the cantilevers 61′, and has amagnetically-attractive interacting portion 851 disposed adjacent to thesecond electromagnet member 84, and an elongate actuating portion 852connected to the interacting portion 851 and disposed directlyunderneath the corresponding one of the cantilevers 61′. The actuatingportion 852 is formed with an upwardly extending actuating projection853. The corresponding one of the cantilevers 61′ is formed with areceiving groove 611 corresponding to the actuating projection 853. Inthis embodiment, the actuating portion 852 has a bottom surface 8521formed with an elongate guiding groove 8522. The base 2′ has a topsurface formed with an elongate guiding rib 23 that engages slidably theguiding groove 8522, as shown in FIGS. 1S and 17.

The first electromagnet member 82 is operable in one of an energizedstate and a de-energized state. The first electromagnet member 82attracts the working plate 83 when in the energized state to moveupwardly the hammer end portion 63′ of the corresponding one of thecantilevers 61′ so as to dispose the corresponding one of thecantilevers 61′ in the suspending position.

The second electromagnet member 84 is operable so as to drive theactuator 85 to move from a holding position, where the actuatingprojection 853 holds the corresponding one of the cantilevers 61′ in thesuspending position when the first electromagnet 82 is operated from theenergized state to the de-energized state, as shown in FIG. 24, to areleasing position, where the actuating projection 853 extends into thereceiving groove 611 in the corresponding one of the cantilevers 61′ soas to permit movement of the hammer end portion 53′ of the correspondingone of the cantilevers 61′ to dispose the corresponding one of thecantilevers 61′ in the pumping position by virtue of the restoring forcein the corresponding one of the cantilevers 61′, as shown in FIG. 17.

In the above embodiments, the optical switch of this invention can alsobe fabricated via a bulk micro machining process, a surface micromachining process, a precision micro machining process, anelectro-discharge micro machining process, a laser micro machiningprocess, etc. Furthermore, since the cantilevers 61 are arranged aroundthe periphery of the deflector 51, the optical switch of this inventionprovides a relatively large space for various arrangements of thecantilevers 61 using conventional low-cost technology.

To sum up, the optical switch of this invention utilizes the period fortransmitting the optical signal to the input module to dispose thecantilever 61 in the suspending position. Then, the cantilever 61 can becontrolled so as to be moved from the suspending position to the pumpingposition within a period of nanosecond-level such that the opticalswitch can be switched at a relatively high speed.

While the present invention has been described in connection with whatis considered the most practical and preferred embodiments, it isunderstood that this invention is not limited to the disclosedembodiments but is intended to cover various arrangements includedwithin the spirit and scope of the broadest interpretation so as toencompass all such modifications and equivalent arrangements.

1. An optical switch for routing an optical signal, comprising: a basehaving a fulcrum shaft; a deflecting member mounted movably on said baseand tiltable about said fulcrum shaft so as to be adapted for deflectingthe optical signal; a plurality of elongate cantilevers disposed on saidbase and arranged around said deflecting member, each of saidcantilevers having a hammer end portion disposed on a periphery of saiddeflecting member, and a coupling end portion opposite to said hammerend portion and connected to said base, each of said cantilevers beingoperable so as to move from a suspending position, where said cantileveris bent such that said hammer end portion is spaced apart from saiddeflecting member, thereby storing a restoring force in said cantilever,to a pumping position, where said hammer end portion strikes saiddeflecting member so as td force said deflecting member. to tilt aboutsaid fulcrum shaft; and a plurality of control units, each of which isdisposed on said base, is operably associated with a corresponding oneof said cantilevers, and is capable of controlling the corresponding oneof said cantilevers to move to an appropriate one of the suspendingposition and the pumping position so as to enable said deflecting memberto tilt to a desired direction.
 2. The optical switch as claimed inclaim 1, further comprising at least one input module adapted forproviding the optical signal to said deflecting member, and a pluralityof output modules, wherein tilting of said deflecting member to thedesired direction results in receipt of the optical signal deflected bysaid deflecting member by a selected one of said output modules.
 3. Theoptical switch as claimed in claim 2, wherein said input module isdisposed on one side of said deflecting member, and said output modulesare disposed on another side of said deflecting member opposite to saidone side.
 4. The optical switch as claimed in claim 2, wherein saidinput module is substantially aligned with said fulcrum shaft, saidoutput modules being disposed around said input module.
 5. The opticalswitch as claimed in claim 1, wherein said deflecting member includes adeflector disposed on said fulcrum shaft, and a set of suspension armsarranged around said deflector and interconnecting said deflector andsaid base.
 6. The optical switch as claimed in claim 5, wherein each ofsaid suspension, arms has a serpentine configuration.
 7. The opticalswitch as claimed in claim 6, wherein each of said suspension arms has awidth that increases in a direction from said deflector to said base. 8.The optical switch as claimed in claim 1, wherein said deflecting memberincludes a deflector having a deflecting side and a mounting sideopposite to said deflecting side, said deflector being formed with aplurality of projections extending radially from a periphery of saiddeflector, said base being formed with a deflector receiving recess,said fulcrum shaft being disposed in said deflector receiving recess,said deflector receiving recess being confined by a confining wall thatextends parallel to said fulcrum shaft, said confining wall being formedwith a plurality of guiding grooves corresponding to said projections onsaid deflector such that said projections are positioned movably andrespectively in said guiding grooves when said mounting side of saiddeflector is disposed on said fulcrum shaft in said deflector receivingrecess, said deflecting member further including a set of magneticplates mounted on said mounting side of said deflector, said base beingfurther provided with a set of permanent magnet blocks in said recessand corresponding to said magnetic plates for stabilizing said deflectorwhere one of said cantilevers strikes said deflector.
 9. The opticalswitch as claimed in claim 1, wherein each of cantilevers is made of amagnetically-attractive material.
 10. The optical switch as claimed inclaim 9, wherein each of said control units includes a mounting memberdisposed on said base adjacent to the corresponding one of saidcantilevers, an electromagnet mounted on said mounting member, and anL-shaped actuator having an intermediate pivot portion, connectedpivotally to said mounting member and pivotable about a pivot axistransverse to said fulcrum shaft, an elongate hooking portion connectedto said intermediate pivot portion and extending toward thecorresponding one of said cantilevers, and a magnetically-attractiveinteracting portion connected to said intermediate pivot portion andtransverse to said hooking portion, said electromagnet being operable inone of an energized state and a de-energized state, said electromagnetattracting said hammer end portion of the corresponding one of saidcorresponding cantilevers when in the energized state so as to enablesaid actuator to pivot about said pivot axis such that said hookingportion moves said hammer end portion of the corresponding one of saidcantilevers to dispose the corresponding one of said cantilevers in thesuspending position, said electromagnet releasing said interactingportion when in the de-energized state so as to enable said actuator topivot about said pivot axis such that said hooking portion permitsmovement of said hammer end portion of the corresponding one of saidcantilevers to dispose the corresponding one of said cantilevers in thepumping position by virtue of the restoring force in the correspondingone of said cantilevers.
 11. The optical, switch as claimed in claim 10,wherein each of said control units further includes an electrostaticplate mounted on said mounting member and disposed above saidinteracting portion of said actuator, said electrostatic plate beingoperable so as to attract said interacting portion of said actuator whensaid electromagnet is in the de-energized state to enable said actuatorto pivot about said pivot axis.
 12. The optical switch as claimed inclaim 1, wherein each of said control units includes a driving memberconnected pivotally to said base and disposed on said base adjacent tothe corresponding one of said cantilevers, said driving member having afirst intermediate pivot portion connected pivotally to said base andpivotable about a first pivot axis transverse to said fulcrum shaft, adriving end portion connected to said first intermediate pivot portionand disposed above the corresponding one of said cantilevers andadjacent to said deflecting member, and a magnetically-attractive endportion opposite to said driving end portion and connected to said firstintermediate pivot portion, a first electromagnet member mounted on saidbase and disposed adjacent to and below said magnetically-attractive endportion of said driving member, a second electromagnet member mounted onsaid driving end portion of said driving member, and an L-shapedactuator having a second intermediate pivot portion connected pivotallyto said driving end portion of said driving member and pivotable about asecond pivot axis transverse to said fulcrum shaft and parallel to thefirst pivot axis, an elongate hooking portion connected to said secondintermediate pivot portion, and extending toward the corresponding oneof said cantilevers, and a magnetically-attractive interacting portionconnected to said second intermediate pivot portion and disposedadjacent to said second electromagnet member, said first electromagnetmember being energized to attract said magnetically-attractive endportion of said driving member so as to enable said driving member topivot about said first pivot axis such that said hooking portion of saidactuator moves with said driving end portion of said driving member soas to hook said hammer end portion of the corresponding one of saidcantilevers when said second electromagnet member is energized toattract said interacting portion of said actuator in order to disposethe corresponding one of said cantilevers in the suspending position,said second electromagnet member being de-energized to release saidinteracting portion of said actuator and enable pivoting movement ofsaid actuator such that said hooking portion of said actuator permitsmovement of said hammer end portion of the corresponding one of saidcantilevers to dispose the corresponding one of said cantilevers in thepumping position by virtue of the restoring force of the correspondingone of said cantilevers.
 13. The optical switch as claimed in claim 1,wherein each of said control units includes a mounting member disposedon said base adjacent to the corresponding one of said cantilevers, afirst electromagnet member mounted on said mounting member, amagnetically-attractive working plate disposed below said firstelectromagnet member, said working plate having a connecting endconnected to said mounting member, and a driving end opposite to saidconnecting end and disposed below said hammer end portion of thecorresponding one of said cantilevers, a second electromagnet membermounted on said mounting member and disposed adjacent to said couplingend portion of the corresponding one of said cantilevers, and a slidingactuator disposed slidably between said base and the corresponding oneo£ said cantilevers, said sliding actuator having amagnetically-attractive interacting portion disposed adjacent to saidsecond electromagnet member, and an elongate actuating portion connectedto said interacting portion and disposed directly underneath thecorresponding one of said cantilevers, said actuating portion beingformed with an upwardly extending actuating projection, thecorresponding one of said cantilevers being formed with a receivinggroove corresponding to said actuating projection, said firstelectromagnet member being operable in one of an energized state and ade-energized state, said first electromagnet member attracting saidworking plate when in the energized state to move upwardly said hammerend portion of the corresponding one of said cantilevers so as todispose the corresponding one of said cantilevers in the suspendingposition, said second electromagnet member being operable so as to drivesaid actuator to move from a holding position, where said actuatingprojection holds the corresponding one of said cantilevers in thesuspending position when said first electromagnet member is operatedfrom the energized state to the de-energized state, to a releasingposition, where said actuating projection extends into said receivinggroove in the corresponding one of said cantilevers so as to permitmovement of said hammer end portion of the corresponding one of saidcantilevers to dispose the corresponding one of said cantilevers in thepumping position by virtue of the restoring force in the correspondingone of said cantilevers.
 14. The optical switch as claimed in claim 13,wherein said actuating portion of said actuator has a bottom surfaceformed with an elongate guiding groove, said base having a top surfaceformed with an elongate guiding rib that engages slidably said guidinggroove.